Ski boots made to date usually comprise stiff outer plastic shells enclosing relatively soft inner boots. The stiff outer shell of a boot functions to provide support and stability to the ankle and lower leg of the wearer under varying conditions as may occur during straight-away, turning and jumping maneuvers. The outer shell of such a prior art boot extends above the ankle of the wearer to provide the necessary strength and support for the lower leg, and, because of its stiffness, makes turning of the ankle difficult since the boot does not usually flex along lines corresponding to the natural movement of the ankle.
It is desirable in many ski maneuvers that the weight of the skier be directed towards the forward part of the skis to provide a direct transmission of force from the legs to the skis. This requires that the skier bend his knees in the forward direction such that for a particular leg the thigh extends generally parallel with a line corresponding to the direction of force to be applied to a ski. Such bending is difficult and uncomfortable with prior art boots because the stiff forward part of the shell prevents sufficient or natural forward movement of the rear of the shell or of any cuff that may be attached to the rear of the shell. The result is that as the leg is bent forward, a gap is formed between the back of the leg and the rear of the inner boot and/or the outer shell thus reducing snug fitting of the boot with the lower leg in turn reducing the support and stability functions of the boot. This loss of a snug fit also allows the heel of the wearer to raise with respect to the heel portion of the shell thus further aggravating diminution of stability and support properties of the boot.
Further a conventionally constructed boot having a stiff shell which completely surrounds the foot and lower leg of a wearer provides little shock-absorbing qualities such that shocks imparted to a ski are transmitted much more directly to the leg.
Conventionally constructed boots having a stiff forward portion overlying the top of the foot tend to bulge or bow outwardly in the area of the boot near where the forefoot area of the sole joins the sides of the shell during forward flexing. This bowing reduces snug engagement of the foot by the inner boot and shell such that the foot may, in some instances, be able to move with respect to the shell causing a still further lessening of control of the ski.
It is therefore an object of our invention to provide for a ski boot construction which will allow a skier to easily bend his knees forward such that forces may be progressively and evenly applied to the forward part of the skis and where the flex lines of the boot correspond to the natural flex lines of an ankle.
It is a further object to provide for a boot construction that will maintain a snug fit between the back of a lower leg and the rear portion of a boot as the leg is bent forward to assure that the heel of the wearer remains in the heel portion of the shell and to provide lateral support to the foot throughout the full range of forward and backward movement of the leg.
It is also an object of the invention to provide for a boot construction which will eliminate significant bow or bulge effect occurring near the foresole area of the boot and boot sides as a leg is bent forward.
It is still a further object of the invention to provide for a boot construction which is shock-absorbing in the upward, rear, forward and side directions and which will provide a spring-back effect tending to return the foot to the normal position with respect to a ski when bending forces are removed.